How come we don't just get a walnut shell blasting every 40k or so, even if out of our pocket? The service is available. We seem to have enough anecdotal evidence now don't we? A speed shop guy cautioned me in June last year to be on the lookout for this. This was when I had the car for only one month so it kinda went in one ear and out the other. And run a good fuel additive and drive it hard. We bought the car to drive it hard anyway, did we not? And get good mileage to partially soothe our conscience.